Cold weather makes it more difficult to start vehicles, and especially commercial vehicles, and most especially commercial vehicles with diesel engines. Several factors contribute to this difficulty of starting.
One factor is the strength of the battery. As battery amperage output is a function of temperature, lower temperatures result in lower battery amperage, which gives the battery less power to turn the engine. This loss of amperage in a battery in cold weather can be substantial. For example, it is not unusual for a battery to lose 35% of its power at 37° F., and as much as 60% of its power at 0° F. The second factor relates to oil viscosity. As the viscosity of an oil tends to increase at decreasing temperatures, the oil within the engine at colder temperatures presents greater resistance to the rotation of the engine than a more free-flowing less viscous oil does at warmer temperatures. In summary, cold weather forces a lower powered battery to overcome increased turning resistance caused by thicker, more viscous oil.
In order to counteract these difficulties, it is quite common to employ a block heater with a commercial vehicle (and even with consumer vehicles in very cold areas such as Alaska. A block heater comprises a probe-like resistive heater that is insertable into an engine component, so that the probe extends into the interior of the engine block, and preferably, into an oil reservoir within the engine.
Many commercial vehicles are fitted with a plug having a removable cap for insertion of the probe. When the cap is removed, the probe can be inserted into the block, so that the heated end of the probe extends directly into the oil within the block, to keep the oil warm.
In addition to the probe described above, other types of engine block heaters exist. For example, there exists dip stick type probes that can be inserted into the oil fill tube where the dip stick normally resides. Another alternative is to employ a resistive heater probe that is placed into the coolant reservoir of the vehicle, rather than the oil reservoir of the vehicle. Additionally, resistive probes can be placed in a fuel reservoir of a vehicle, such as a gas tank, since heavier fuels, such as diesel fuel have a tendency to become gel-like at very low temperatures.
Heater probes of the type described above typically come in two primary varieties—permanent and removable. In this regard, many vehicles come equipped with heater probes that are permanently installed in the vehicle. At night, one connects a plug to an outlet on the heater block, to thereby connect the source of electricity to the heater probe. In other situations, a removable heater probe is used, such as the dipstick heater probe. In such cases, the heater probe and plug are connected to the block and unconnected to the block every time that the device is being used.
Heater probes of the type described above can be used either singly or in combination. For example, some facilities provide a first heater that is insertable into the oil reservoir, and a second heater that is insertable into the coolant reservoir. Some facilities will even employ three probes, with the third probe being disposed within the gas tank of the vehicle to keep the fuel from becoming gel-like.
The extent to which a company will employ probes to keep its vehicles warm is largely dependent upon the type of vehicles that are employed by the company, and the nature of the climate in which the vehicles operate. Clearly, a company operating a fleet of diesel powered delivery vehicles in Manitoba would likely employ a more extensive array of vehicle heating devices than a company operating a fleet of gas powered vehicles in a relatively warmer southern area such as Kentucky or Tennessee.
Typically, a fleet operator will couple these heaters through a cord to a plug that is disposed on the wall of the garage in which the vehicle is kept, or may be placed on an electricity station within the parking lot or parking area in which the vehicle is placed. A typical procedure for employing the engine heaters is to insert the heaters into their appropriate reservoir (coolant, oil, fuel) when the vehicle is parked at the end of its shift, and to allow the heater to operate during the time that the vehicle is parked, until such time as the vehicle is ready for use on its next shift. At such time, the heaters will be disconnected from the source of electricity, and the vehicle will be driven away.
Most known vehicle heaters in use today are equipped with controls that comprise little more than an on-off functionality. Usually, the act of connecting the heater to a source of electricity, such as by plugging it in, causes the heater to actuate and begin its operation. Similarly, the outlets that are typically used in connection with such vehicle heaters operate similarly to other conventional outlets, as they are normally defaulted to be in a “on position”, wherein they can provide current to any device that is plugged into the outlet. Many such outlets include a switch for controlling the flow of electricity to the outlet that can take the form of a localized switch that is dedicated to the outlet, or else a circuit breaker type switch that may control a plurality of outlets.
In commercial operations, the most typical setup is to employ a single circuit breaker that controls a single outlet. This single breaker-single outlet arrangement is used because a typical vehicle heater such as a block heater, fluid coolant heater or fuel heater will often draw about 1300 watts of power. Because of this high-power draw, it has been found that a single circuit breaker should generally not be used to control the operation of more than one outlet.
Although the devices described above perform their function in a workmanlike manner, room for improvement exists. As described above, the vehicle heater for a commercial vehicle draws a significant amount of power that results in significant costs for the electricity used to power the heater. As such, it would be desirable to provide a heater that provides a more efficient operation, and draws less electricity than the heaters described above. By drawing less electricity, a “smarter” system would have the potential to save the Heel operators significant amounts of money due to the reduced energy consumption.
The following example illustrates the lack of efficiency in the current systems. In school bus operations, the busses are typically started and begin their morning routes somewhere around 6:00 a.m. These morning routes are often finished by 9:00 a.m. or 10:00 a.m. After the morning routes are finished, the busses then sit idle in their parking areas from about 10:00 a.m. to about 2:00 p.m. when the afternoon routes begin. The afternoon routes typically keep the buses engaged between 2.00 p.m. and 5:00 p.m. or 6.00 p.m. At 6:00 p.m., the buses return back to their parking areas and are parked overnight with the engines shut off until the next morning at 6:00 a.m., when they are again restarted. Additionally, some buses may be operated into the evening hours, such as those buses that are used for transporting students to special events, such as sporting events.
In the scenario set forth above, the school bus driver typically connects his vehicle to the block heater during the day time non-use frame between the morning and afternoon bus routes (approximately 10:00 a.m. to 2:00 p.m.) and then again during the evening, non-use time frame between the end of the evening routes and the beginning of the next morning routes which lasts between approximately 6:00 p.m. and 6:00 a.m.
In the scenario given above, the heater would be drawing current at a fairly substantial rate for a 16-hour period each day. This 16-hour period is not significantly different from the operation of a commercial fleet, where the trucks are operated on a single shift. In such cases, the trucks would generally be operated between about 8:00 a.m. and 6:00 p.m. and connected to a heater block between 6:00 p.m. and 8:00 a.m. the next day. However, a primary difference between the operation of a school bus fleet and a commercial vehicle fleet is that a school bus fleet will have two idle (non-use) periods, with the first being between the morning and afternoon routes, and the second being overnight, whereas a commercial operation will have only a single idle time.
Although the above-described schedules are likely to apply to most of the vehicles within a respective school bus or commercial vehicle fleet, exceptions apply. As discussed above, some school buses are used in the evening for after school or evening events. Similarly, some of the commercial vehicles may be used at times other than the standard day shirt, or may be used for more than one shift during a day. As such, it would be beneficial to have some individual control over the electricity provided to individual vehicles, to enable the operator to accommodate vehicles having different schedules and different requirements.
One object of the present invention is to provide a device that is capable of efficiently controlling the operation of a vehicle maintenance device, such as a block heater for a vehicle, and especially a commercial vehicle.